Question

The IUPAC name of $\left[Ni\right(N{H}_3{)}_4\left]\right[NiC{l}_4]$ is

• A. Tetrachloronickel(0)-tetraaminenickelate(II)
• B. Tetramminenickel(II)-tetrachloronickel(II)
• C. Tetraamminenickel(II)-tetrachloronickelate(II)
• D. Tetrachloronickel(II)-tetraaminenickelate(0)

Answer 1

The correct option is C Tetraamminenickel(II)-tetrachloronickelate(II)

$\left[Ni\right(N{H}_3{)}_4\left]\right[NiC{l}_4]$
Here, 4 chlorido ions are present. Since nickel shows an oxidation state of 0 and +2, the anion could have a -4 or -2 charge respectively.
We can easily rule out the -4 charge if we look at the cation. $N{H}_3$ is a neutral ligand and since nickel shows oxidation states of +2 and 0, the cation cannot possibly have a +4 charge to balance out the -4 charge on the anion.
Hence, both the anion and cation must have nickel in its +2 state. Now the rest is simple and the name would be: Tetraamminenickel(II) tetrachloridonickelate(II).